Air-compressor motor.



D. E. C'ROUSE; C. G. EIDSON & T. DAVIS. AIR COMPRESSOR MOTOR.

APPLlcAnoN man :uu/23.1914.

Patented Jan. 11, 1916.

2 SHEETS-SHEET l.

Arion/vifs www D. E. GROUSE, C. G. EIDSON & T. DAVIS.

AIR COMPRESSOR MOTUR. APPLICATION FILED IuLY 23. I9I4.

1,168,251. Patented Jan.11,1916.

l 2 SHEETS-SHEET 2.

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DAVID E. cEoUsE AND CHARLES G; E'IDsoN, or ANNAPoLIsaND THOMAS DAvIs, o-E

. BALTIMORE, MARYLAND.

AIR-COMPRESSOR MOTOR.

Specication of Letters Patent.- V Patented Jan, 11, 1916.

Application filed July 23, 1914. Serial No. 852,677.

To all whom 'it may concern:

Be it known that we, DAVID E. GRoUsE and CHARLES G. EIDsoN, citizens ofl the United States, and residents of Annapolis, in the county of Anne Arundeland State of Maryland, and THOMAS DAVIS, a citizen of the United States, and a resident of Baltimore, in the State of Maryland, have made certain new and useful Improvements in Air-Compressor Motors, of which the folreservoir, and which 'may subsequently beVv used as a motor when the compressed air in the ltank is admitted intothe cylinders of the device.

A further object of our invention is to provide novel means for shifting certain parts so as to' change from the air compressor to the motor orvice versa.

A further object of our invention is to l provide means for positively holding certain valves to their seats when the device is used as an air compressor.

Other objects and advantages will appear in the following specification, and the novel features of the invention will be particu! larly pointed out in the appended claims.

Our invention is illustrated in the accompanying drawings forming part' of this application in which similar reference characters indicate like parts in the several views, and in which,

Figure 1 is a partial plan view of the device, Fig. 2 is a central longitudinal section -Ithrough the device when the latter is being used as a motor, Fig. 3 is a section'on the line 3 3 of Fig. 1, Fig. 4 is a View similar toFig. 2 showing the parts in the position for using the device as an air compressor, Fig. 5 is an enlarged section on the line '5-5 of Fig. 1, Fig. 6 is an enlarged section on the line 6 6 of Fig. 1, Fig. 7 is a perspective view showing the construction of the piston valve, Fig. 8 is a diametrical section through the piston valve, and Fig. 9 is a detailed sectional view of a three-way valve, the same being a modified form. p

In carrying out our invention we provide a main crank shaft 1 which is supported in suitable bearings 2 carried by the ends 3 of the crank case 4c. Asy will be seen from Figs. 2 and 4 we provide four cylinders A, B, C and D having the pistons a, b, c and d 'respectively disposed therein, the pistons a and b being connected to the crank shaft 1 at 180 apart, while the pistons c and d are connected to the crank shaft 1 at 180 apart from each other and 90 from the pistons a and respectively.

Each cylinder is provided with a port,

' such as those shown at a, b', c and'afrespectively. These ports serve both as inlet and exhaust ports when the device is to be used as a motor, but are closed when the device is to be used as an air compressor, as will be explained later.

lAttached to the main cylinders is a valve casing 5 which is closed at its ends. One of these ends 6 is provided with an opening arranged to receive the reduced extension 7 of an auxiliary cylinder 8, and within the cylinder 8 is an auxiliary piston 9 whose stem 10 extends through the reduced extension 7 and is connected with a bell-crank lever 11 which is pivotallymounted at 12 and whose other arm is disposed in the path of a push rod 13 which is normally held in an upper position by means of a spring 14. This push rod extends into operative engagement with f an eccentric 15 disposed on the shaft 1. The

similar to the cam 15. The cams 15 and 15 are 90 apart on the crank shaft so that when one of the push rods is up the other is half way down.

The cylinder 8 is closed by an end member 16. which is secured to a rod or shaft 17.

Disposed on the shaft 17 are piston valves 18 and 19. A second shaft 10 has an enlarged portion upon which are disposed piston valves 20 and 21 and a reduced portion which is operatively connected with the bellcrank lever 11X. The piston valves 18, 19, 20 and 21 are designed to control the ports a', b', c and d respectively.

Referring now to Fig. 6 we have shown therein a section through the cylinder A from which it will be seen that the cylinder is provided with an inlet valve 22 and with an outlet check valve 23. The latter communicates by means of a pipe 24 with the air reservoir 25. The cylinder B is similarly provided with intake' and outlet check valves, both the outlets of the cylinders A-B communicating with the tank 25 by the common pipe 24. rlhe cylinders C and D are not provided with these valves, since the two cylinders A and B are entirely suflicient to compress air.

The pistons 18 and 19 are preferably of the form shown in Figs. 7 and 8, although pistons of another form might be used. From an inspection of Figs. 7 and 8 it will be seen lthat we provide a split ring 18a having a recess 18b on one edge thereof. This ring is designed to fit over a body portion 18c which is provided with a head 18d substantially flush with the outer edge of the ring. p The head has a beveled portion 18e. The body portion 18c is provided with a pin 18b arranged to extend through a recessed portion 18g at the ends of the split ring. The Vpiston when assembled-has the appearance shown in Fig. 8. It may be secured to the shaft 17' in any suitable manner.

From the foregoing description of the various parts of the device the operation thereof may be readily understood.

Let us assume that the device is to be used as an air compressor. yThe crank shaft is turned. The movement of the cam 15 will cause the upward movement of the pushy rod 13 when the cam is on the upper side of the shaft,l as shown in Fig. 4, thereby moving inwardly the piston 9. As soon as the piston reaches the head 16 it moves the latter together with the cylinder 8 and the rod 17, to which the head is connected, so as to bring the piston valves 18 and 19 over the ports a and b. The piston valves 20 and 21 it will be noted are brought substantially into the position shown in Fig. 4, it being only necessary when the device is used as a compressor that the ports Aa and b of the cylinders A and B be closed. Further revolution of the crank shaft will result `merely in the idle play of pistons c and ci', the piston-valves 18 and 19 remaining over their ports. When the piston a is descending it will draw in air through the inlet valve 22, see Fig. 6,

vand when itis ascending it will force the air out from the check valve 23 into the res-y voir becomes charged bythe movement of i the pistons a and b in thecylinders A and B.

`When now it is desired to use the device as an air motor the valve 26'in the pipe 27 is operated, thereby'admitting air through the branch pipes 28-and 29, see Fig. 2, into the space between the piston valves 18 and 19 and between the piston valves 20 and 21. Part of this air pressure will pass by means of a by-pass 17 X in the shaft 17 into the space between the head 16 and the piston 9'in the auxiliary cylinder 8, thus causing the stem 10 to which the piston 9 -is attached to move outwardly. This forms a cushion of air between the piston 9 and the head 16 of they auxiliary cylinder 8 thereby increasing the effective length of the stem 10 in the shaft 1'7 so as to control the valves 18 and 19 when the device is to be used as a motor, so that when the piston 9 is again moved inwardly it will cause the auxiliary cylinder 8 to move with it, and will thus move the shaft 17 bearing the piston valves.

rlhe `means for maintaining the piston stem 10 of the piston 9 in its 'outward position is shown in Figs. 1 and 3. In these figures it will be seen that when the valvey 26 is operated air is admitted by means of a' pipe 30 into a cylinder 31 carried by the Aframe of the device, see Figs. 1, 3 and 5,

and forcing the plungers 32 and 33 in said cylinder apart against their seats. This tends to compress the springs 34 and 35 which thereupon force outwardly their respective plungers 36 and 37 against armsY 38 and 39 respectively, that are secured to the pivot shafts 40 and 41 respectively. The springs 34 and 35 are so tensioned as to keep these bell-crank levers in their outer position. Now as the main crank shaft revolves the bell crank levers are engaged by the push rods 13 and 13X, so as to shift the piston valves 18, 19 and 20, 21. In Fig. 2 the piston a of the cylinder Ay is moving in the direction shown by the arrow, and air is coming in at the port a. The

- piston Z) of the cylinder'y B is moving so as to exhaust the air in the cylinder through the port b. The piston c of the cylinder C is taking in air through the port c while the piston d of the cylinder D is exhausting from the port d. The cylinder 5 is provided with exhaust ports 42, 43, and 44. It lwill be seen that the compressed air passes in to the cylinders A and B between the piston valves of the set of valves 18-19. The air passes into the cylinders C and D between the piston valves 20-21 while the exhaust in each instance takes place on the outside of these pistons, so that the ports a', b', cv', d act as inlet and exhaust ports.

.v shaft 17, however, being arranged to slide t It will be observed that the piston valves 18 and 19 have the cut-away portions 18",

see Fig. 7. When the device is used as a motor these valves are in the position shown in Fig. 2 in which it will be observed that the vcut aw-ay portion now leaves a valve of comparatively small width, or of just such," size as to insure avoidance of lap and when the device is being used as an air compressor the full width of the valve is used,"as shown in Fig. 4. This necessitates the rotation of the valve and'it is' accomplished in the following manner: As `will b e seen from Fig. 5 there is a second auxiliary cylinder 45 which is provided with -a vplunger 46. When air is first admitted through the pipe 27X this plungerI is forced down upon a seat 47 and presses a spring 48 which is-contained within theplunger stem. The lower part of the stem is :provided with a rack arranged to engage a segmental gear 49 which is feathered to the shaft 17- so as to causev rotation of the latter, the

through the gear longitudinally of fits axis.

When pressure is admitted through the pipe 27 therefore, the piston valves 18 and 19 are turned so as to 'being them into the position shown in Fig. 2, thus exposing the small width of the piston valve to that part of the Acylinder containing the ports a We lhave found by experience that the pressure inside the cylinders A and B v.will tend tov .raise the valves so as to cause leakage `when the device isused as a compressor and 'i to lock the valves down against this presinder 8 to escape through the by-pass 17",

ports, it being understood as explained, that these valves do not move when the device is being used as an air compressor. When the device is to be used as an air compressor, a push valve 52 is operated to relieve the air pressure between the piston valves 18 and19, thuspermitting the air in the cyland permitting the piston 9 in the cylinder 8 to move up near the head 16, as shown in Fig. 4. The release of the air from the .pipe 27 permits the plungers 32 and 33 see Fig. 3, to approach each other under the action of the springs 34 and 35. This permits the bell crank nlevers 11" and 11X to assume positions in which they will not be,

operated by` .thercams "When the airis released from the cylinder 45 the spring 48 will rotate the segmental gear 49 so as to llevers 11 and 11x in such a position that whenthe device'is being used as an air mol tor the piston valves will be operated by the movements of the cam rods 13 and 13". When the air is relieved in the cylinder 31 the spring tension is/withdrawn from the bell-crank levers by the retraction of the pistons 32 and 33, as heretofore explained.

Instead of using the two valves 26 and 52 We may use a single three-way valve like that shownv in Fig. 9. In this figure it will be seen that the valve 53 has passa es which may establish communication eit er with the pipe 27 and the exhaust,` as shown in Fig. 9, or ywhen rotated indirectly, as shown by the curved arrow. that portion of the pipe 27 leading to the pressure reservoir may be connected with the' other portion of.

foot lever (not shown) to bring the device to operate as a motor for startin the engine where on the release of the va ve it Will be returned to its normal position shown in Fig. 9, thereby permitting the device to operate as an air compressor.

1. In acombined air motor and compressor, a plurality of cylinders each provided withQan inlet check valve and an outlet check valve and each having a single port serving as an inlet port and an outlet port, a valve casing common to all of said cylinders, an individual piston valve in said valve casing for each of said ports, means for shifting said piston valves from one side of its individual port to the other when the device is being used as a motor, means for shifting thepiston valves to cover certain of said ports when the device is being used as an a1r compressor, and automatic. means for locking the piston valves which cover the ports against the pressure within the cylinders.

2. In a combined lair motor and compresser, a plurality of .cylinders each provided with an inlet check valve and an outlet check valve, and eachv cylinder having a single port serving as an inlet port and an outlet port. a valve casing common to all of said cylinders. a shaft disposed therein, a

plurality of piston valves carried bvsaid" l shaft. means for moving the shaft longitudinally of its axis so as to bring theY valves into position to cover the `portsI when the de1`v1ce 1s used as an air compressor, an eccen-l tric cam carried by said shaft, a spring pressed "plunger arranged to engage said cam, and automatic means for rotating said shaft yto bring' the cam in position'to lock the piston valvesagainst. pressure Within the cylinder. p

3. In a combined air motor and compressor, a plurality of cylinders each provided With anl inlet check valve and an outlet check valve,`and each cylinder having a single port serving as an inlet port and an outlet port, a valve ycasing common to all of said cylinders, a shaft disposed therein, a plurality of piston valves carried by said shaft, means for moving the shaft longitudinally of its axis so as to bring the valves into position to cover the ports when the device is used as an air compressor, an eccentric cam carried by said shaft, a spring pressed plunger arranged to engage said cam, automatic means for rotating said shaft to bring the cam in position to lock the piston valves against pressure Within .the

cylinder, said last named means comprising a segmental gear feathered to the shaft so as to rotate the shaftwhen the gear is rotated, but to permit the longitudinal movement of the shaft on its axis, and pneumatic means for operating the gear.

4. In a combined air motor and com-4 pressor, a plurality of cylinders eachA prosingle port serving as an inlet port .and an outlet port, a valvecasing common to all of said cylinders, a shaft disposed therein, a

plurality of iston valves carried by saidshaft, means or moving the' shaft longitudinally of its axis so as to bring the valves into position to cover the ports when the de-v vice is used as an air compressor, an eccentric cam carried by said shaft, a 4spring pressed plunger arranged to engage said cam,. automatic means for rotating said shaft to bring the cam in position to lock the piston valves against pressure Within the cylinder, said last named means comprising a segmental gear feathered to the shaft so as to rotate the shaft When the gear is rotated, but to permit the longitudinal movement of the shaft on its axis, an auxiliary air cylinder, a spring pressed piston disposed Within said air cylinder and having an integral rack arrangedA to' engage the gear, the admission of air into the -auxiliary cylinder serving to rotate the gear in one direction and the Withdrawal of air causing the rotation of the gear in the other direction through the expansion of the spring.

5. In a combined air motor and compressor, a plurality of cylinders each provided With an inlet check valve and an outlet check valve, each cylinder having a single port which serves as an inlet port and an outlet port, a valve casing common to all of said cylinders, a shaft disposed in said valve casing, a plurality of piston valves carried by said shaft, said piston valves each having a reduced peripheral portion, and automatic means for bringing said reduced peripheral portion in posltion to'pass over said ports When the device is being used as a motor.

6. In a combined air motor and compressor, a plurality of cylinders each provided With an inlet check valve and an outlet check valve, each cylinder having a single port Which servesas an inlet port and an outlet port, a valve casing common to all of said cylinders, a shaft disposed in said valve casing, a plurality of `piston valves carried by said shaft, said piston valves each having a reduced peripheral portion, vand automaticmean-s for rotating said piston valves to bring the-reduced portion into position to move past the ports when the device is being used as' a motor and for reversely rotating the piston valves so as to bring the reduced portions out of registration with the ports When the device is being used as an air compressor. 7. In a combined air motor and compressor, a plurality of cylinders each provided With an inlet check valve and an outlet check valve and each having a single port serving as an inlet port and an outlet port, -a valve casing common to all of said cylinders,.a crankshaft, an auxiliary shaft in said valve-casing, a bell-crank lever operatively connected with the auxiliary shaft in said valve casing, means operated by the crank shaft for moving the bell-crank lever,

spring means 'for exerting tension on the bell-crank lever, pneumatic means for automatically applying the spring tension on the bell-crank lever, said pneumatic means comprising a cylinder, a spring-pressed plunger 8. In a combined' air motor and com-v pressor, a plurality of cylinders, /each provided With an inlet check valve and an outlet check valve and each cylinder having a single port serving as an inlet po-rt and an outlet port, a'valve casing common to all of said cylinders, piston valves in said valve casing for controllmg said ports, means for shifting said piston valves over said ports when the device iis used as a motor, the shutting ofi' of the motive fluid servingv to permit the valve actuating device to move certain of the valves yso as to cover certain of lthe ports, and means for automatically locking the valves covering the ports'against pressure from Within the cylinders.

9. In a combined air mptor and compresser, a 4plurality of cylinders each provided With an inlet',v check valve and an outlet check valve and each cylinder having a single port serving as an inlet port andan outlet port, a valve casing common to said cylinders, a crank shaft, an auxiliary shaft in said valve easing, a bell-crank lever operatively connected with the ,shaft in saidl valve casing, means operated by the crank shaft for moving the belle'crank lever, and 10 pneumatically controlled spring means for exerting pressure on the'bell-.crank lever.

` DAVID E. CROUSE.

CHAS. G. EIDSON. THOMAS DAVIS. -Witnessesz` j' .1 -W. THURMAN, G. S. STOUT. 

